Using coroutines

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour
{
    // coroutines have to return IEnumerator
    IEnumerator TestCoroutine()
    {
        Debug.Log("Test");
        yield return new WaitForSeconds(5);
        Debug.Log("Will display after 5 seconds");
    }

    void Start()
    {
        // to make coroutines work, you have to call them
        // using StartCoroutine
        StartCoroutine(TestCoroutine());
    }


    void Update()
    {
        // invoke the coroutine whenever left mouse button is pressed
        if (Input.GetMouseButtonDown(0))
        {
            // you can call coroutines from Update
            StartCoroutine(TestCoroutine());
        }
    }
}